1. Field of the Invention
The present invention relates to a recovered toner classifier to be used in an image forming apparatus, such as a copying machine, a facsimile, a printer, and other similar devices, and more particularly to a recovered toner classifier that can effectively classify recovered toner into toner to be reused and toner to be disposed of.
2. Discussion of the Background
An image forming apparatus generally includes a cleaning device. The cleaning device is provided to recover residual toner remaining on an image bearing member, such as a photoconductive element and intermediate transfer belt after a toner image has been transferred onto a transfer sheet. The cleaning device is also provided to a sheet conveying device, which conveys the transfer sheet having the toner image thereon to a fixing device, to recover unfixed toner (i.e., residual toner).
FIG. 11 is a schematic drawing illustrating a sectional view of a toner recycle device having components arranged around a photoconductive drum, and a recovered toner conveying path in a background image forming apparatus. A charging device 17, a cleaning device 18, a developing device 19 and a transfer device 20 are arranged around a photoconductive drum 16. A recovered toner conveying mechanism 21 is provided between the cleaning device 18 and developing device 19.
In recent years, the demand for effective use of resources is constantly increasing. Thus, the need for recycling toner removed from the photoconductive drum 16, etc., is growing. Various types of devices, which convey toner recovered by the cleaning device to a developing device or a toner replenishing device, have been proposed. Because recovered toner includes an aggregation of toner having large particle size and paper lint, if the recovered toner is reused as it is, an abnormal image is produced, such as an image having black spots and blank portions.
In Japanese Patent Laid-Open Publication Nos. 6-337589, 10-207236, 7-77906, and 10-260583, a recovered toner classifier having a mesh filter is discussed. The recovered toner classifier is provided between the recovered toner conveying mechanism 21 and developing device 19 to remove the aggregation of toner and paper lint in the recovered toner.
In the toner recycle device discussed in Japanese Patent Laid-Open Publication No. 6-37589, recovered toner is conveyed into the recovered toner classifier. A recovered toner replenishing roller then presses the recovered toner disposed on the filter to crush the aggregations of toner. The toner passing through the filter is then conveyed to the developing device for reuse. In the toner recycling device discussed in Japanese Patent Laid-Open Publication No. 10-207236, the filter is provided in a mid-portion of the recovered toner conveying path. A disposal toner conveying path is provided below the filter. Thus, the toner remaining on the filter is reused. In a recovered toner classifier discussed in Japanese Patent Laid-Open Publication No. 10-260583, the recovered toner conveyed through a recovered toner conveying path is conveyed into a cylindrical-shaped filter. The filter is then vibrated to classify the recovered toner into toner to be reused and toner to be disposed of.
However, in the devices discussed in the above-described Japanese Patent Laid-Open Publications, recovered toner including a large aggregation of toner and paper lint may not be satisfactorily classified into toner to be reused and toner to be disposed of.
The present invention has been made in view of the above-mentioned and other problems and addresses the above-discussed and other problems.
The present invention advantageously provides a novel recovered toner classifier that can effectively remove foreign substances such as paper lint included in recovered toner, and crush aggregations of toner in the recovered toner.
According to an example of the present invention, the recovered toner classifier includes a rotatable cylindrical-shaped filter having an inlet for the recovered toner at one end of the filter in a direction of its length and an outlet for discharging the disposal toner at the other end of the filter, and a fur brush having a brush spirally provided on an outer peripheral surface of a rotation shaft and a non-brush region continuously formed from the inlet of the filter for the recovered toner through the outlet of the filter for discharging the disposal toner along the axis line of the rotation shaft. The fur brush is concentrically contained in the filter such that the fur brush integrally rotates with the rotation shaft with a tip portion of the brush in press-contact with an inner peripheral surface of the filter. A screw conveyer having a screw provided on a portion of the rotation shaft on a side of the inlet of the filter for the recovered toner is arranged to convey the recovered toner to the inlet of the filter for the recovered toner.